Virtual screening and molecular growth guide the design of inhibitors for the influenza virus drug-resistant mutant M2-V27A/S31N.

The influenza A virus matrix protein 2 (AM2) protein is a proton-gated, proton-selective ion channel essential for influenza replication that has been identified as an antiviral target. The drug-resistance of the M2-V27A/S31N strain, which has been growing more prevalent in recent years and has the potential to spread globally, prevents current amantadine inhibitors from having the desired impact. In this study, we compiled the most common influenza A virus strains from 2001-2020 from the U.S. National Center for Biotechnology Information database and hypothesized that M2-V27A/S31N would become a common strain. The lead compound ZINC299830590 was screened for M2-V27A/S31N in the ZINC15 database using a pharmacophore model and molecular descriptors. This lead compound was then optimized by molecular growth, which allowed us to identify important amino acid residues and create interactions with them to produce compound 4. Molecular dynamics simulation showed that the complex of compound 4 and M2-V27A/S31N had certain degrees of stability and flexibility. The binding free energy of compound 4 was calculated using the MM/PB(GB)SA method and totaled -106.525 kcal/mol. Finally, physicochemical and pharmacokinetic profiles were predicted using the Absorption, Distribution, Metabolism, Excretion, and Toxicity model, which indicated the good bioavailability of compound 4. These results provide the basis for further in vivo and in vitro studies to demonstrate that compound 4 is a promising drug candidate against M2-V27A/S31N.Communicated by Ramaswamy H. Sarma.

Adsorption and desorption of flavonoids on activated carbon impregnated with different metal ions.

In this study, four metal ions Mg2+, Al3+, Fe3+, and Zn2+ were loaded on the surface of activated carbon by an impregnation method coupled with high-temperature calcination to prepare modified activated carbon. Scanning electron microscopy, specific surface area and pore size analysis, X-ray diffraction, and Fourier infrared spectroscopy were used to evaluate the structure and morphology of the modified activated carbon. The findings show that the modified activated carbon had a large microporous structure and high specific surface area, both of which significantly improved absorbability. This study also investigated the adsorption and desorption kinetics of the prepared activated carbon for three flavonoids with representative structures. The adsorption amounts of quercetin, luteolin, and naringenin in the blank activated carbon reached 920.24 mg g-1, 837.07 mg g-1, and 677.37 mg g-1, while for activated carbon impregnated with Mg, the adsorption amounts reached 976.34 mg g-1, 963.39 mg g-1, and 817.98 mg g-1, respectively; however, the desorption efficiencies of the three flavonoids varied a lot. The differences in desorption rates of naringenin as compared with quercetin and luteolin in the blank activated carbon were 40.13% and 46.22%, respectively, and the difference in desorption rates increased to 78.46% and 86.93% in the activated carbon impregnated with Al. The differences provide a basis for the application of this type of activated carbon in the selective enrichment and separation of flavonoids.

Comparison of Target Pocket Similarity and Progress into Research on Inhibitors of Picornavirus 3C Proteases.

The 3C protease (3C Pro) plays a significant role in the life cycle of picornaviruses from replication to translation, making it an attractive target for structure-based design of drugs against picornaviruses. The structurally related 3C-like protease (3CL Pro) is an important protein involved in the replication of coronaviruses. With the emergence of COVID-19 and consequent intensive research into 3CL Pro, development of 3CL Pro inhibitors has emerged as a popular topic. This article compares the similarities of the target pockets of various 3C and 3CL Pros from numerous pathogenic viruses. This article also reports several types of 3C Pro inhibitors that are currently undergoing extensive studies and introduces various structural modifications of 3C Pro inhibitors to provide a reference for the development of new and more effective inhibitors of 3C Pro and 3CL Pro.

Intake of Sugar Substitute Gummy Candies Benefits the Glycemic Response in Healthy Adults: A Prospective Crossover Clinical Trial.

Sugar reduction in food has attracted great health concerns worldwide. Gummies have been one of the most popular and highly favored candies due to their chewable properties, simplicity to swallow, and delicious taste. The general perception is that gummies raise blood sugar levels, but the truth is that gummies with the right formula can control glycemic response. The purpose of this study is to investigate the effects of the gummy dosage form and sugar types on the glycemic response control. Maltitol and erythritol as sweetener alternatives were applied in gummy candies (total and partial sugar substitutes gummy, T-SG and P-SG), with sucrose-based gummies used as comparisons (CG). A prospective crossover study was then conducted on 17 healthy adults. The effects of different types of gummies on glycemic response in healthy adults were evaluated on the basis of the participants' glycemic index (GI) and glycemic load (GL) values. Every three-day interval, participants took CG, P-SG, T-SG, and glucose solution, respectively, and the theoretical glucose conversion content was kept the same in all groups for each trial. Each participant performed four tests with each sample and recorded the changes in blood glucose after food consumption. It was found that all three types of gummies slowed down subjects' glycemic response when not taken in excess, and the improvement effect was in the trend of T-SG > P-SG > CG. Both P-SG and T-SG were low-GI candies (54.1 and 49.9). CG that was not consumed in excess of 17.2 g had a high GI (81.9) but a low GL (<10). Texture analysis and in vitro digestion were used to explore the effect of gummy matrix on glucose release. T-SG and P-SG retained a higher hardness and were less hydrolyzed to release glucose during digestion compared with CG. Additionally, experiments have revealed that gummies can reverse the poor glucose tolerance in women. In conclusion, gummies are a good carrier for dietary supplements due to their sustained-release characteristic of available carbohydrates and provide healthier options for people in control of glucose homeostasis.